Astrophysics

, Volume 49, Issue 1, pp 3–18

Masses of the local group and of the M81 group estimated from distortions in the local velocity field

  • I. D. Karachentsev
  • O. G. Kashibadze
Article

DOI: 10.1007/s10511-006-0002-6

Cite this article as:
Karachentsev, I.D. & Kashibadze, O.G. Astrophysics (2006) 49: 3. doi:10.1007/s10511-006-0002-6

Abstract

Based on high precision measurements of the distances to nearby galaxies with the Hubble telescope, we have determined the radii of the zero velocity spheres for the local group, R0 = 0.96±0.03Mpc, and for the group of galaxies around M 81/M 82, 0.89±0.05Mpc. These yield estimates of MT = (1.29±0.14)· 1012 M and (1.03±0.17)· 1012 M, respectively, for the total masses of these groups. The R0 method allows us to determine the mass ratios for the two brightest members in both groups, as well. By varying the position of the center of mass between the two principal members of a group to obtain minimal scatter in the galaxies on a Hubble diagram, we find mass ratios of 0.8:1.0 for our galaxy and Andromeda and 0.54:1.00 for the M82 and M81 galaxies, in good agreement with the observed ratios of the luminosities of these galaxies.

Keywords

GalaxiesLocal groupM81 group-galaxiesmasses

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • I. D. Karachentsev
    • 1
  • O. G. Kashibadze
    • 2
  1. 1.Special Astrophysical ObservatoryRussian Academy of SciencesRussia
  2. 2.P. K. Shternberg State Astronomical InstituteRussia